The fact that Who's Who was in Seastone Cuffs when the 'Free or all" battle in Level 6 happened makes his defeat not as bad as it seems. Sure SJW was also in Seastone Cuffs but he's a giant so his Physical strength should be above Human Who's Who anyway
To be fair the most of the prisoner had seastone cuffs, they where overall the most criminal pirates, it isn´t bad if WsW lose to one of BB top dogs, Sengoku and the whole navy where shocked to see these monsters, based on the information these four had the highest bounties. We can easily assume that these four had bounties over 600mio if not even more.
Barges was pretty strong, he was the next threat to Doffy in DR, he was portrayal alongside with Doffy as the biggest threat for Luffy.
I doubt that Pica or Vergo could match or bring Barges in problems.